Operator for roll top doors



Feb. 9, 1937.

E. H. MCCLOUD OPERATOR FOR ROLL TOP DooRs Original Filed May 25, 1952 7 Sheets-Sheet 1 "ITF .aus

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lll/l1 NVENTOR Edw a T'cZ ZMQCZoud BY 9s ATTORNEYS Feb. 9, 1937. E. H. MccLoUD V2,070,058-

OPERATOR FOR ROLL TOP DOORS Original Filed May 25, 1932 'T Sheets-Sheet 2 VENTOR EDWALB) H. MCLOUD.

BY FIG- 2 if ATTORNEY Feb. 9, 1937. E. H. MccLoUD 2,070,058

OPERATOR FOR ROLL TOP DOORS Original Filed May 25, 1932 7 Sheets-Sheet 3 ATTORN EY S Feb. 9, 1937. E, H. MccLoUD 2,070,58

OPERATOR FOR HOLL TOP DOORS Original Filed May 25, 1932 7 Sheets-Sheet 4 INVENTOR EDWARD H. MS CLOUD.

ATTORNEYS Feb. 9, 1931. E. H. MCCLOUD 2,070,058

OPERATOR FOR ROLL TOP DOORS Original Filed May 25, 1932 7 Sheets-Sheet 5 xNvENToR 4l EDWARD H. MSCLOU D.

ATTORNEYS Feb. 9, 1937. E. H. MccLouD OPERATOR FOR ROLL TOP DOORS Original Filed May 25, 1932 7 Sheets-Sheet 6 INVENTOR y Edward H. MCLoucL ATTORNEYS Feb. 9, 1937. :-:.V H. MccLouD 2,070,058

OPERATOR FOR ROLL TOP DOORS Original Filed May 25, 1932 7 Sheetls-Sheet 7 Mlm/crm# Maa/vir CHAIN/NG WIND/AIG D002, DUCK.

ops/vm@ Marax. cLo s /A/G u//N D ma WND/NG /ls I l je] Fzy. f6

l Pds/l Burro# STAT/0d n INVENTOR Edward HMQCZOLLCL v- ATTORNEYS Patented Feb Q, i193? attenta PATENT OFFICE 2,010,058 OPERATOR Foa ROLL Tor Doons Edward H. McCloud, Columbus, Ohio, assigner to The Kinnear Mfg. Company, Columbus, Ohio,

a. corporation of Ohio Continuation of application Serial No. 613,429, May 25, 1932. This application April 13, 1936,

Serial N0. 74,061

18 Claims.

This invention relates to improvements in operating mechanism for roll top doors and has for its object to provide in such mechanism a carriage for opening and 'closing the door and means for supporting the carriage for longitudinal movement.

It is an object of the invention to provide such means wherein the carriage is reciprocated on its supporting means by a chain which is connected at each end to the carriage on an adjustable mechanism whereby undesirable slack in the chain may be prevented by adjustment of the chain supporting mechanism on the carriage.

It is a. further object of the invention to provide means 'comprising a drawbar having one end pivotally mounted on the carriage and the other end provided with pivotal means of connection to the door whereby longitudinal reciprocation of the carriage is transmitted into lifting and swinging of the door and wherein means is provided in such connection between the drawbar and door for resiliently resisting undue shocks upon the operating parts and for adjusting the effective length of the drawbar.

It is a further object of the invention to provide means for reciprocating the drawbar carriage, which means includes an overload clutch which is so adjustable that, upon occurrence of binding of parts or other impediment to the movement thereof, breakage of the partswill be prevented by the opening of the clutch when a delinite predetermined torque is exceeded and wherein objectionable frictional wear` caused by the operation of such clutching mechanism is reduced It is a further object of my invention to provide an overload element in the driving mechanism which functions, upon the occurrence of undue resistance to the motion of the door, such as obstruction by the top of an automobile, to prevent the breakage of parts due to theproduction of undue torque in the driving mechanism for the door.

It is a further object of my invention to provide such means wherein operation of the overload mechanism to prevent breakage of parts will not disturb the timing of the door travel because of the location of the timing mechanism between the door and the overload mechanism.

rThese andother advantages will appear from the following description taken in connection with the drawings.

This application is a continuation of my application Serial No. 613,429, flied, May 25, 1932,

which matured into Letters Patent No. 2,062,593 granted December 1, 1936.

Referring to the drawings:

Figure 1 is a front'elevation of a roll top 'door Figure 4 is a top plan view of the door operaty ing mechanism of my invention;

Figure 5 is a side elevational View of the motor and trackway, showing the motor brake mecha--l nism and associated parts;

Figure 6 is a side elevational view of the carriage and attached ends of the sprocket chain, showing a fragment of the drawbar pivoted to the carriage;

Figure 7 is a. bottom plan view of the carriage shown in Figure 6;

Figure 8 is an end elevational view of my supporting means for the sprocket chain;

Figure 9 is a detail view taken on a section through a part of the door, showing the mode of attachment of the drawbar to the door;

Figure 10 is a view of the drawbar supporting bracket shown in Figure 9;

Figure 11 is an end view of the carriage, showing in section the trackway upon which the carriage is supported;

Figure 12 is an enlarged side elevational view of the operating mechanism located on the end of the carriage trackway, as seen from the right of Figure 4;

Figure 13 is an elevational view, partly in section, taken through the casing of the limit switch of my invention and showing my overload release mechanism in side elevation;

Figure 14 is an elevational view in section of the drive and overload mechanism shown in Figure 13;

Figure 15 is an enlarged view oi the hub part of the overload device of my invention, the portions of the pulley having been broken away;

Figure 16 is a diagrammatic view of the electric wiring used in the operation of the mechanisms of my invention.

While the present door operating mec is adapted to be used with the various forms of roll top overhead doors and in connection withl buildings of various forms of construction, I

have, in the drawings, disclosed the attachment thereof to a door 3 which is adapted'to close the doorway 2 of the building having walls I and the casing 4 surrounding the doorway 2.

Suitably located at each side of the doorway and supported by the walls or ceiling of the building, are guide members, each comprising a vertically disposed portion 5, a horizontally disposed portion 6', and an arcuate portion 1 connecting the vertical and horizontal portions (see Figure 3). 'Ihese guide members, of which there are two, are adapted to guide each side of the door. 'Ihe vertical portions of these guides are closely adjacent the sides of the doorway, while the horizontal portions thereof extend horizontally above the doorway Vin order to support the door in its open position. The horizontal portions of the guideways are supported by means of suitable brackets 8 attached to the wall or any other part of the building. Suitably supported above the doorway by the ceiling or any other part of the building, is a trackway comprising a pair of spaced parallel angle irons. The horizontal portion of one angle iron is indicated by the .numeral 9, while the horizontal portion of the other angle iron is indicated by the numeral 9a.

The vertical part of the first angle iron is indicated by the numeral I0, While the vertical part of the second is indicated by the numeral I0a. The trackways are supported by means of bracket II disposed at each end and at the intermediate portion thereof,- and at one end of the trackway is mounted a sprocket I2 supported by the bracket I3, while a sprocket I4 and shaft I4a are suitably supported at the other end upon the trackway.` 'Ihe position of the trackway with respect tof-that of the guide members is clearly illustrated in Figure 3.

' Mounted to travel on the trackway is a carriage I5, which has a pair of rollers I6 rotatably mounted at one side thereof and a single roller I8 rotatably mounted at the other side thereof (Figures 6 and 7). At one side of the carriage I5, between the rollers I6 is an outwardly extending flange I1, which is adapted to engage beneath the horizontal part of one of the track members and cooperate with the rollers I6 to hold the carriage I5 on the trackway. At the opposite side of the carriage is a pair of flanges I9 which engage beneath the horizontal part of the other track member and cooperate with the roller I8 therebetween to hold the carriage on the trackway. This arrangement of rollers produces three-point contact of the carriage on the trackway, whereby misalignment of the trackway does not disturb the support of the carriage thereon. 'Ihe two rollers may be arranged to travel along the part 9 of one track or along the part 9a of the other track. Disposed about the sprocket wheels I2 and I4 and having each end thereof attached to the carriage I5 is a sprocket chain 2li. The respective ends of the chain are attached to the carriage by means of lugs 2I at either end of the carriage. Cooperating with each 'lug 2| is a washer or plate 22 secured to the lug by means of a screw 23. The lugs 2| are adjustable toward and from each other and may be adjusted by means of the connecting screw 24-in order that the tension on the chain may be varied or the slack thereof taken up (see Figure 7).

Arranged at either side of the screw 24 on the underside of the carriage I5 are lugs 25 through which extend a pin or pintle 26 by means of which the upper end of the drawbar 21 is pivotally attached to the carriage I5. A plurality of holes which is abutted by the plate or washer 32 exlo tending about the shaft below the pin 33. In abutment with the lower side of the plate or washer 32 is a spring 35, surrounding the drawbar 21, which has the other end thereof in abutment with a, plate or washer 34 which is similar l5 to the plate or washer 32 and is disposed about the drawbar 21 in the same manner. The washer 34 is adapted for abutment with the peripheral surface of the above described shaft 29. The

shaft 29 may be referred to as the drawbar pivot 20 shaft. On the opposite side of the shaft 29 and surrounding the drawbar 21 is a plate or washer 39 which is similar to the plate or washer 34 and which engages the shaft` 29 in the same manner.

Disposed about the drawbar 21 and having abut- 25 ment with the lower surface of the plate or washer 39 is a second spring 4I), the opposite end of which abuts aplate or washer 38 which is disposed about the drawbar 21, as are the other plates or washers. of the drawbar 21 for engagement with the lower face of plate or washer 38 is the adjusting nut 36 and lock nut 31 which operates in a well known manner to secure the parts in any desired position, which is achieved by means of the adjust- 35 ing nut 36. vIt will be clear that the distance between the pin 33 and the plate or washer 36 is subject to variation by movement of the ad-v liusting nut 36 on the drawbar 21, and by this means the effective length of the drawbar 21 may 40 be closely adjusted, while adjustment by large increments may be achieved by selectively moving the pin 33 from one to another of the above described holes 28 in the drawbar 2L By this means the tension of springs 35 and 40 may also 45 be adjusted, and it is thus to be seen that by means of the pin 33 and adjusting nut 36 the effective length of the drawbar 21 and the tension of springs 35 and 40, which ac t as shock absorbing means, may be adjusted as desired, and 50 that the adjustment may be made permanent by the cooperation of the lock nut 31 with the adjusting nut 36. The bracket 30 is attached to the door 3 by means of bolts 4I. The above described attachment means provides a yielding connec- 55 tion between the drawbar and the door so that abrupt movement of the door will be prevented from causing excessive jarring, vibration Ior breakage of the operating machinery.

As shown particularly in Figures 3 and 8, 60

means is provided for supporting the sprocket chain 20, which means comprises a pair of castings 42 disposed between and resting upon the horizontal portions 9 and 9a and connected in spaced relation by means of a tie bar 43, which 65 has each end attached by means of a bolt to one of the castings 42. Each casting 42 has an upper stirrup member 44 of substantial U-shape, which is adapted to support the upper reach of the sprocket chain 20 and disposed at the lower 70 end of each casting is a lower stirrup 45 of form similar to that of 44, which is adapted to support the lower run of the sprocket chain 20. The chain support comprising the two castings 42 and the tie bar 43 is supported upon the portions 75 Threaded on the lower end 30 9 and 9a-for sliding movement therealong, which movement is caused by the abutment of the carriage I5 with one of each of these castings," vat each end of the' travel of the carriage I5 along the trackway. Adjacent the operating mechanism and mounted on the trackway is the stop j member 46 (Figure 4). The sprocket wheel I4 is supported on -the shaft l4a which is mounted in suitable bearings 48 on thetrackway (Figure 14). Adjacent the sprocket wheel I4 and rigidadapted to receive complementary projections 55A,

located om the adjacent and abutting face of a pulley 54 which is located upon the shaft 48a adjacent to the disk 52. The pulley 54 is rotatably mounted upon the shaft 48a, but is urged toward the disk 52 by the spring 51. which surrounds the shaft 48a and abuts a washer which is in contact with anadjusting nut 56. The nut 58 is threaded on the shaft 48a and has suitable keyways therein, whereby the nut 56 may be locked in adjusted positionby means of a pin or key extending through suitable pin or keyholes in the threaded portion of the shaft 48a. By this means, the compressive effect of the spring 51 may be varied as desired, whereby to denitely limit the amount of torque which may be transmitted from pulley 54 to and through sleeve 5I, shaft 48a, gear 58, gear 41, and sprocket I4, through sprocket chain 28 to carriage I5, and through drawbar 21 to the door 3. It is thus clear that, if an obstruction be interposed in the path of the door 3 in operation, the pulley 54 will slide axially along the shaft 48a against the pressure of the spring 51 and allow free rotation of the drive pulley 54 with respect to the disk 52, sleeve 5i and shaft 48a, whereby to prevent the generation of excessive torque and consequent damage to or breakage of parts of the mechanism. I'he pulley 54 is equipped with a groove 58, in which is disposed a belt 59, which belt 59 connects the pulley 54 for rotation with the pulley 68, which is mounted on the shaft 66 of the motor 6i. 'I'he motor 6l is suitably supported upon the members 9, I8 and 9a, Illa forming the trackway for the carriage |5.

As shown particularly in Figure 12, the motor 6|! may be secured to the trackway by means of a bracket 62, which bracket 62 is adjustably secured by means 63, 64 to the respective rails of the trackway. By means of this adjustment, it is possible to move the motor 6I longitudinally of the trackway, whereby to adjust the tension of the belt 59 and then lock the bracket in adjusted position to prevent vibration of the motor. The meansfor performing this adjustment comprises a bolt 65 attached to one end of the trackway and having a nut thereon in engagement with a flange disposed at one end of the bracket 62, as shown particularly in Figure 4. On one side of the bracket 62 are downwardly disposed arms 61 and 68 having the ends thereof spaced apart for reception of the motor shaft 66 and associated parts therebetween. Pivoted by means of a pintle 1| to the arm 61 is an upper brake member or brake jaw 18 and a lower brake member or brake jaw 68. The opposite or free ends of these brake jaws or members are Yconnected by means of the boit 12 which has threaded at the upper end thereof a conventional adjusting and lock nut assembly, generally designated 14. Disposed between the adjusting nut and the upper surface of the brake member or jaw 18 is the spring 13. The free ends of the members 69 and 18 are thus urged together by the force of the spring 13 which may be adjusted by the adjusting and lock nut members, generally designated 14. At the extreme end of the brake member or jaw 18 is threadedly mounted an adjusting screw 18 having a lock nut 19 thereon. Disposed between the free ends of the brake members or jaws 69 and 18 is a stud or pintle 16 having a brake lever 15 mounted'for pivotal movement thereabout. One extreme end of the lever 15 has a projection 11 thereon, which is adapted to engage the adjusting screw 18 for a purpose which will be hereinafter described. The lower brake member or jaw 69 has threaded therein an ad justing screw 88, similar to the adjusting screw 18 and equipped with a lock nut 8l, whereby the set screw 88 may be locked in adjusted position with respect to brake member 69. The opposite end of the lever 15 is steeply inclined upwardly and has pivoted thereto a link 85, which link is also pivoted to the armature 84 of a solenoid 83 which is supported on a bracket 82, which bracket is preferably supported at one end of one of the track members and which may, however, be rigidly attached to the arm 61 of the bracket 62.

The operation of the braking mechanism is as follows: with the parts in the position shown in Figure 5, the free ends of the brake members 69 and 18 are drawn together by the force of the spring 13 and the engagement of the projection 11 of the brake lever 15 with the adjusting screw 18 and the further engagement of the adjusting -screw 88 with the lever 15 tends to rotate or swing the lever 15 upwardly or in an anti-clockwise direction as seen in Figure 5. The upward swinging movement of the lever 15 draws the link 85 and armature 84 upwardly. In this position, the solenoid 83 is de-energized and the brake members 69 and 18 forced inwardly, whereby to closely engage a brake drum 66a which is rigidly secured to the motor shaft 86. In this position, when the solenoid 83 is de-energized, the

brakes are thus applied and rotation of thea motor shaft 66 is therefore made impossible. When the solenoid88 is energized, the armature 84 and link 85 are drawn downwardly whereby to swing the brake lever 15 clockwise about its axis, whereupon the engagement of the lever with the adjusting screws 18 and 88, above described, will spread the free ends of the brake jaws or members 69 and 18 against the force of the spring 13, whereby to free the brake drum 66a from the braking action of the brake members or jaws 69 and 18 and allow free rotation thereof. The connections of the motor and solenoid with the source of power is such that the solenoid is energized to release the brake and the motor energized for operation of the mechanism simultaneously.

As shown particularly in Figure 13, the controlling switch for the motor and solenoid is operated by the shaft I4a, upon which is rigidly rzounted the chain drive sprocket I4. The switch mechanism is enclosed in a case or housing 83 and comprises a screw shaft 81 having each end the case or housing 86 and which screw shaft 81 has a pin 99 extending axially through one end thereof, which pin 89 is adapted to engage slots 90 at the adjacent end of the shaft |4a. 'This end of the shaft |4a has a recess therein for the reception of the adjacent end of the screw shaft 1 one another by a tension spring 98 attached to the upper ends thereof. ABelow the tension spring and screw threaded in the arm 92 is a screwhavthereto.

'nut'|0|. "switch arm 93 is an adjusting screw having the stop |00 thereon and lock nut |02. The stops 99 and |00 are oppositely disposed and are adapted for abutment with the downwardly extending portion of the switch operating member 9| upon its travel in opposite directions. The switch arm 92 is mounted on a pivot member 94, while the switch arm 93 is mounted on a switch arm 95. At the lower end of the switch lever 92 is a contact 96, while the lower end of the switch arm 93 is equipped with a similar contact 91. These contacts are equipped with conventional binding posts for the attachment of suitable power leads Opposite the contact 96 and suitably mounted for cooperation therewith is a xed contact |03 which is equipped with a suitable binding post and mounted on a suitable support which is attached rigidly to the casing or housing 86. A like fixed contact 04 is similarly equipped with a binding post and likewise mounted on a xed support which is rigidly attached to the switch casing or housing 86. Upon rotation of the pulley 54 in one direction, which is transmitted to cause movement of the sprocket I4 in one direction, the switch operating member 9| is moved to the right whereby to engage the stop |00 and separate contacts 91 and 04 which are normally in contact. Upon rotation of the pulley 54 in the opposite direction, the direction of the sprocket |4 will be reversed and the switch operating member 9| will travel to the left, whereby to contact stop 99 and separate contacts 96 and |03 which are normally in engagement. The contacts |03 and |04 are connected, as shown in Figures 4 and 5, by means of an electrical conduit |06 to the-terminal box |05 which is mounted on one of the members comprising the trackway. Below the terminal box |05 is the magnetic switch |01, from which extends a cable |08 containing electrical connections to the motor 6| and solenoid 33. A suitable source of current isdeslgnated by lines |09 and ||0 (Figure 16).

The details of the wiring diagram are shown in Figure 16 and the connections made thereby are as follows: the supply wires |09 and H0, which serve to supply current for operating the door, are connected to a constant source of power. The wire |09 extends to contacts and |I2 in the magnetic switch and to a common connection between the limit switches or arms 92 and 93 (shown in this figure to be closed) and eneigizes one side of both the open operating coil ||3 and the closed operating coil ||4 and also one side of the magnetic brake 03. The wire H0, which is likewise connected to a constant source of power, directly energizes the contacts l5 and ||6 in the magnetic switch, and also the contacts ||1 and 2,070,055 Y j f ||8 in the magnetic switch by means of a parallel circuit extending through stop button- ||9 and wire |20. This parallel circuit of the wire ||0, through wire |20, energizes one side of the open button |2| and one side of the closed button |22. The terminal A|23 of the magnetic switch is connected to the open' button by means of wire |24 and to the open operating coil ||3 in a magnetic switch by means of wire |25. The motor 6| is of the three-lead type, electrically reversible, repulsion start induction type.. The windings |26 and `|21 are the repulsion windings, the windings |26 being used when the motor rotation is to be such as to cause the door to open, and the windings |21 being used when the door is to be closed. These windings |26 and |21 are both short-circuited as soon as the motor reaches induction motor speed, thereby causing the wire, which is connectedV to either of these windings |26 or |21, to be reconnected automatically to the induction winding |28 at the point where it is common to both |26 and |21.

The terminal |29 of the magnetic switch is connected by wire |30 to the repulsion starting winding |26 of the motor, which when energized, causes the motor to rotate in a proper direction to open the-door. Terminal |29 is also connected by wire |3| to one side of the contact Terminal |32 in the magnetic switch is connected to the induction running winding |28 of the motor by means of wire |32a, and must be connected thereto regardless of the direction of rotation of the armature of the motor. The terminal |32 is also connected to one side of the brake magnet 83 by means of Wire |320. Terminal |32 is also further connected to the contacts H5 and H6 by wires |32b. The terminal |33 in the magnetic switch is connected to the repulsion starting winding |21 of the motor by means of a wire |34, which when energized causes the motor to rotate in the proper direction to cause closing of the door. This terminal |33 is connected by means of wire |35 to one part of the contact ||2. Terminal |36 in the magnetic switch is connected to-the closed push button by means of wire |31 and to the close operating. coil in the magnetic switch by means of wire |38, and further through the close operating coil to the contact |03 by the wire |39. The contact |09 is connected through wire |25a to the open operating coil 3, which is connected by a wire |25 to the terminal |23.

When the open push button is operated, a circuit to open the operating coil in the magnetic switch is completed through wires |20, |20 and |25 to the coil, then through wire |2611 to the limit switch arm 93, and out through the common wire |09., thereby causing contacts ||1 and i6 in the magnetic switch to be closed. The brake magnet 83 is directly connected to the wire |09 and is connected by wire |32c through terminal |32 to contacts ||5 and the magnet switch, which completes the circuit and causes the brake to release, freeing the motor for rotation. The wire |09 is connected through contacts and terminal |29 in the magnetic switch to the repulsion starting winding |26 of the motor 6|, and the wire ||0 is connected through contact H5 and terminal |32 in the magnetic switch to the induction running winding |28, which causes the motor to begin to rotate in 'the proper direction to cause the door to open. Since the door operates by a momentary contact of the push button, it is necessary to have a maintaining circuit to the open operating coil in the magnetic switch. This circuit is through the stop button ||9, wire |20, contact II'I, to the terminal |23, and through wire `to the coil, then through wire |25a to the switch arm 93, and out through the common wire |09.

If, while the motor is running, either the stop button is operated or the-limit switch 93 opens due to being. struck by the traveling switch operating member 9|, the circuit to the open operating coil is broken, thereby causing contacts I I, l1 and ||5 in the magnetic switch to open, cutting oi the current to the motor and brake. The brake, which is spring set, then engages the brake drum 66a on the motor shaft 66 and the friction of the brake shoes on the brake members 69 and 10 stops the rotation of the motor armature, thereby stopping the operation of the door. The closing operation is similar` to the opening operation, except that the closed button is operated, which causes contacts IIS, ||8 and H2 in the magnetic switch to close, whereby to energize winding |21 of the motor, which starts the rotation of the motor in the proper direction to close the door. The stopping is again accomplished either by operating the stop button IIS or by the operation of the limitswitch arm 92 breaking the circuit, instead oi' arm 93, as was the case when the door was open.

It is to be understood that the above description is illustrative and in no wise limiting and that I desire to comprehend within my invention such modifications and variations as are necessary to adapt my invention to varying uses and that I therefore desire to comprehend such modifications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I cla-im as new and desire to secure by Letters Patent, is: v

1. In an operating mechanism for a door adapted to be moved and swung in its guides upwardly from a vertical position in a doorway to a horizontal position above the doorway by operating means including a horizontally movable carriage supported on a trackway mounted independently of the guides; means for operatively connecting said carriage to said door comprising a drawbar having one end pivotally attached to said carriage and having the opposite end slidably and pivotally attached to a bracket on the door, said last-named end of said bar having thereon means adapted to resiliently resist slidable movement of said bar with respect to said bracket and means' on said bar for adjusting said resilient resistance whereby to compensate for changes in the effective weight of the door due to variation in weather conditions.

2. In an operating mechanism for a door adapted to be moved and swung in its guides upwardly from a vertical position in a doorway to a horizontal position above the doorway by operating means including a horizontally movable carriage supported on a trackway mounted independently of the guides; means for operatively connecting said carriage to said door comprising a drawbar having one end pivotally attached to said carriage and having the opposite end slidably and pivotally attached to a bracket on the door, said last-named end of said bar having thereon means to resiliently resist slidable movement of said bar with respect to said bracket and means for adjusting said resilient resistance and for varying the eiective length of said drawbar, whereby to adjust said resilient resisting means and for varying the effective length of said drawbar whereby to vary the operating characteristics of the mechanism to compensate for changes in the weight oi the door due to variation in weather conditions.

3. In an operating' means for a door adapted to be moved and swung upwardly in guided movel Y ment from a. vertical position in a doorway to a said door, said trackway having an idler sprocket at one end and a sprocket at the, other end thereof adapted to be reversibly driven by means including an overload clutch, a sprocket chain supported by said sprockets and -att'ached at each end to said carriage and a chain guide slidably mounted on said trackway, said chain guide comprising a .pair of rigidly spaced castings each having a pair of stirrups adapted to support the upper and lower reaches of the chain against sagging, said castings being spaced at opposite sides of the carriage on the trackway and being adapted to be slidably moved along the trackway by said carriage at the' end portions of the carriage travel, whereby to prevent sagging of the sprocket chain adjacent the., carriage throughout its travel.

4. In an operating means for a door adapted to be moved and swung upwardly in guided movement from a vertical position in a doorway to a horizontal position above said doorway; a horizontally disposedtrackway independently mounted above said doorway, a carriage mounted for rolling three-point contact on said trackway. a drawbar pivoted at one end .to said carriage and adjustalrily, pivotally, and resiliently attached at the other end to said door, said lastnamed connection providing shock absorbing means and means for adjusting the shock absorbing means and for changing the effective length of the drawbar, said trackway having an idler sprocket at one end and a sprocket at the other end adapted to be reversibly driven by means including an overload clutch means, a sprocket chain supported by said sprockets and attached at each end to an adjustable bracket on the carriage, and a chain guide slidably mounted on said trackway, said chain guidecomprising a painof rigidly spaced castings each having a pair of stirrups adapted respectively to support the upper and lower reaches of the chain against sagging, said castings being disposed at opposite sides of the carriage on the trackway and being adapted to allow free movement of the carriage therebetween during a portion of the carriage travel and being adapted to be slidably moved along the trackway by the carriage at the end portions of the carriage travel in order to lprevent sagging of the sprocket chain adjacent the carriage during its travel on the doorway.

5. In an operating means for a door adapted to be moved and swung upwardly in guided movement from a vertical position in a doorway to a horizontal position above said doorway, said means including a trackway having a carriage mounted for rolling movement thereon, a drawbar pivoted at one end to the carriage and resiliently and pivotally connected at the other end to said door; means for causing reciprocation of said carriage on said trackway comprising a pair of spaced sprockets mounted adjacent the ends of said trackway, a sprocket chain -chain to said carriage, said last-named means comprising a pair of brackets one rigidly and one slidably mounted on said carriage for movement toward and away from one another and each adapted to support one end of said sprocket chain, and means for adjusting sait' brackets with respect to one another comprising an adjusting screw threadedly mounted in each of said brackets and extending longitudinally of said sprocket chain whereby the .slack in the sprocket chain may be adjusted by adjustment of said brackets with respect to one another.

6. In an operating means for a door adapted to be moved and swung upwardly in guided movement fromA a vertical position in a door-4 way to a horizontal position abovesaid doorway, said means including a trackway having a carriage mounted for rolling movement thereon, al

drawbar pivoted at one end to the carriage and resiliently and pivotally connected at the other end to said door; means for causing reciprocatlon of said carriage on said trackway comprising a pair Aoi? spaced sprockets mounted adjacent the ends of said trackway. a sprocket chain supported by each of said sprockets and means for adjustably attaching the ends of said sprocket chain to said carriage, said last-named means comprising a pair of brackets one rigidly and one slidably mounted on said carriage for movement toward and away from one another and each adapted to support one end of said sprocket chain, and means for adjusting said, brackets with respect to one another comprising an adjusting screw threadedly mounted in each of said brackets and extending longitudinally of said sprocket chain and additional means for preventing sagging of said sprocket chain, said means comprising a pair of castings spaced apart by a tie bar rigidly attached to each, said castings including portions adapted respectively to support the upper and lower reaches of said sprocket chain and said castings being disposed at opposite sides of said carriage and slidably supported on said trackway, whereby said Acarriage will reciprocate freely between said castings and will slide said chain support along the trackway during portions of y the carriage travel whereby to prevent sagging of the sprocket chain in either the top or bottom reach thereof adjacent' the carriage during its travel.

7. In a power driven operating, means for a roll door top adapted to travel in guides from a vertical position. in the doorway upwardly to a.v horizontal position above the doorway; a horizontally disposed trackway above the doorway, a carriage on said trackway having rolling contact therewith, asprocket mounted at each end of said trackway, one of said sprockets being driven by means including an overload clutch driven by a reversible prime mover, a chain supported by said sprockets and connected at each end to said carriage, a chain guide comprising a pair of rigidly spaced castings each having stirrup means for supporting the upper and lower reaches of said chain against sagging, and a drawbar having one end pivotally attached to said carriage and the other end adjustably, resiliently, and pivotally connected to said door.

8. In a power driven operating means for a roll door top adapted to travel in guides from .a vertical position in the doorway upwardly to a horizontal position above the doorway; a horiby means including an overload clutch driven by a reversible p'rime mover, a chain supported by said sprockets and connected at eachend to said carriage, a chain guide comprising a pair of rigidly spaced castings each having stirrup means for supporting the upper and lower reaches of said chain against sagging, and a drawbar pivotally attached to said carriage at one end and having the opposite end adjustably and resiliently connected to a pivoted bar attached to said door by means adapted for adjustment of the resiliency of said connection and of the eiective length `\Qf said drawbar, whereby to adjust the effective length of said drawbar and alter the operating characteristics of the operating means to compensate for'change in weight of said door due to weather conditions.

9. In a power driven operating means for a roll top door adapted to travel in guides from a vertical position in the doorway lupwardly to a horizontal position above the doorway; a horizontally disposed trackway above the doorway, a carriage on said trackway having rolling threepoint contact therewith, a sprocket mounted at each end of said trackway, one of said sprockets being driven by means including an overload clutch driven by a reversible prime mover having brake means adapted to hold the rotor thereof against rotation when said motor is 'de-energized. a chain supported by said sprockets and connected at each end to said carriage, a chain guide comprising a pair of rigidly spaced castings each having stirrup means for supporting the` upper and lower reaches of said chain against sagging,

and a drawbar having one end pivotally attachedv on the trackway providing. for alignment of the carriage on said trackway irrespective of misalignment of said trackway, and the connection of said drawbar to said door providing means for adjustment of the resiliency of said connection and of the effective length of said drawbar whereby to change the operating characteristics of the operating means to compensate for changes in weight of the door due to changes in weather conditions.

10. In a power driven operating means for a roll top door adapted to travel in guides from a vertical position in the doorway upwardly to a horizontal position above the doorway; a horizontally disposed trackway above the doorway, a carriage on said trackway having rolling threepoint contact therewith, a sprocket mounted at each end of said trackway, one oi said sprockets being driven by means4 including an overload clutch driven by a reversible prime mover having brake means adapted to hold the rotor thereof against rotation when said motor is de-nergized,

Vertical position in the doorway upwardly to a horizontal position above the doorway; a ,horizontally disposed trackway above the doorway, a carriage on said trackway having rolling threepoint contact therewith, a sprocket mounted at each end of said trackway, one of said sprockets being driven by means including an overload clutch driven by a reversible prime mover having brake means adapted to hold the rotor thereof against rotation when said motor is de-energized, a chain supported by said sprockets and connected at each end to an adjusting means on said carriage, a chain guide comprising a pair of rigidly spaced castings each having stirrup means for supporting the upper and lower reaches of said chain against sagging, and a drawbar pivotally attached to said carriage at one end and having the opposite end adjustably and resiliently connected to a pivoted bar mounted in a bracket on said door,` the connection of said drawbar to said pivoted bar being adapted to provide for adjustment of -the resiliency of said connection and for changing the effective length of said drawbar whereby to change the operating characteristics of the operating means to compensate for change in weight of the mechanism -operated due to abnormal weather conditions.

12. In an operating means for a roll top door including a trackway, a' carriage reciprocated thereon by a sprocket supported chain. and a drawbar pivotally connected at one end to said carriage and to the door at the other; a chain support comprising a pair of spaced castings having a tie bar therebetween and rigidly attachedl to each, each of said castings having means thereon for supporting the upper and lower reaches of said chain and being slidably supported on said trackway at opposite sides of the carriage, whereby said carriage will reciprocate freely between the castings during a part of its travel but will slide the chain support along the trackway during end portions of the carriage travel whereby to prevent sagging of the chain adjacent the carriage during the full carriage travel.

13. In an operating means for a roll top'door including a trackway, a carriage reciprocated thereon by a sprocket supported chain, and a drawbar pivotally connected at one end to said carriage and to the door at the other; a chain support comprising a pair of spaced castings having a tie bar therebetween and rigidly attached to each, each of said castings having` a pair of vertically spaced stirrups thereon for supporting respectively the upper and lower reaches of said chain and being slidably supported on said trackway at opposite sides of the carriage, whereby said carriage will reciprocate freely between the castings during a part of its travel but will slide the chain support along the trackway during the end portions of the carriage travel whereby to prevent sagging of the chain adjacent the carriage during the full carriage travel.

14. In an operating means for a roll top door including a trackway, a carriage supported thereon for three-point rolling contact therewith and for reciprocation by a sprocket supported chain, said carriage having a drawbar pivotally attached thereto and to the door; the pivotal connection of said drawbar with said door comprising a bracket rigidly attached to said door, a horizontally disposed bar pivotally supported in said bracket, a radially disposed bore in said horizontally disposed bar receiving the end portion ci said drawbar, a compression spring surrounding the drawbar and held in compression between stop means on said drawbar and said horizontally disposed bar, and a second compression spring surrounding said'drawbar on the opposite side of said horizontally disposed bar and held in compression between said horizontally disposed bar and stop means on the end of said drawbar.

15. In an operating means for a roll top door includingV a trackway, a carriage supported thereon for three-point rolling contact therewith and for reciprocation by a sprocket supported chain,- said carriage having a d-rawbar pivotally attached thereto and to the door; the pivotal connection of said drawbar with said door com- .prising a bracket rigidly attached to said door,

a horizontally disposed bar pivotally supported in saiqd bracket, a radially disposed bore in said horizontally disposed bar receiving the-end portion of said drawbar, a compression spring surf rounding the drawbar and held in compression between stop means on said drawbar and said horizontally disposed bar, and a second compression spring surrounding said drawbar o n the opp'osite side'of said horizontally disposed bar and held in compression between said horizontally disposed bar and adjusting nut means threaded on the end of said drawbar, whereby the shock absorbing effectof said springs may be. adjusted to, compensate for diierent conditions of door operation.

16. In an. operating means for a roll top door bracket, a radially -disposed bore in said horizontally disposed bar receiving the end portion of said drawbar, a compression spring surrounding the drawbar and heldin compression between said horizontally disposed bar and a pin disposed in one of aplurality of spaced radial pin receiving holes in saiddrawbar above the horizontally disposed pivoted bar, and a second compression spring surrounding said drawbar on the opposite side of said horizontally disposed bar and held in compression between said horizontally disposed bar and adjusting nut means threaded on the end of said drawbar, whereby the shock absorbing eiect of said springs may be adjusted and the effective length of said drawbar varied by said adjusting nut means within narrow limits and whereby such adjustment may be made in large increments by shifting the pin from one to another of the pin receiving holes in the drawbar. I

17. In an operating mechanism for a door adapted to be moved and swung in its guides upwardly from a'. vertical position in a doorway of a structure to a horizontal position above the doorway by operating means including a horizontally movable carriage supported in a threepoint roller contact on a trackway, and pivotally connected to a drawbar having resilient pivotal connection with the door; said trackway being mounted on said structure independently of the door guides and said drawbar having means in its connection tothe door for varying the effective length of the drawbar whereby to compensate for relative movement between the trackway and guides due to sagging of the structure supporting them.

having portions adapted to Support the upper and lower reaches of said chain, said chain guide being slidably supported on said trackway and adapted to be moved along the trackway by the carriage during the end portions of its travel to 5 prevent sagging of the chain.

EDWARD H. MCCLOUD. 

